Secure SRT323 installation

This question doesn’t really belong here but I’m going to try anyway as no-one else (manufacturer, retailer) seems to be able to help. I want replace my old Drayton Lifestyle ETS1 thermostat with a Secure SRT323 Z-Wave one. The wiring of my Drayton is:

EST1 Terminals
1 = Common
2 = Switched Live
3 = Earth
4 = Neutral

Will that wiring work with the Secure SRT323 and if so - how do I wire it up? The Secure manual is totally confusing to me and I don’t want to break the unit.